Final answer:
The null hypothesis when testing for a difference in test scores between two groups is that there is no difference in test scores between the groups. It is symbolized as H0 and is the hypothesis assumed to be true at the start of the test.
Step-by-step explanation:
When a researcher wants to test whether there is a difference in test scores between two groups, the null hypothesis should be that there is no difference in test scores between the two groups. The null hypothesis, often symbolized as H0, is a statement of no effect or no difference, and it is the hypothesis that is initially assumed to be true. The alternative hypothesis, Ha or H1, is the statement that there is an effect or a difference, and it is what the researcher is trying to establish as true. Therefore, the correct null hypothesis in this context would be option B: There is no difference in test scores between the two groups.
This hypothesis is what the researcher will test against, and through statistical analysis, the researcher will either reject or fail to reject this null hypothesis based on the data collected. The null hypothesis for this experiment should be option B) There is no difference in test scores between the two groups. In hypothesis testing, the null hypothesis is the statement of no effect or no difference. It assumes that there is no relationship or no difference between the groups being compared. In this case, the researcher wants to test whether there is a difference in test scores between two groups. Therefore, the null hypothesis should state that there is no difference in test scores between the two groups.